Preparation of cyclopentadiene resin



Patented Jan. 1, 1946 2.392.140 I rnrzrsaa'rron or orcnornu'ranmua ansmHoward L. Gerhart, Milwaukee, Wis asoignor to Pittsburgh Plate GlassCompany, Allegheny County, -Pa., a corporation of Pennsylvania NoDrawing. Application December 3, 1943,

Serial No. 51am 7. Claims. (creep-2s) The present invention relates tothe preparation of a modified or copolymer resin containin a dienehydrocarbon as a main reactive constituent, and it has particularrelation to the preparation of a copolymer of cyclopentadiene and anunsaturated glyceride oil. a

One object of the invention is to prepare a hard, tough, chemicallyresistant and water resistant resin, or an oily resinous body capable ofhardening to such state from cyclopentadiene and an unsaturated oil.

A second object is to provide a simple and in: expensive process ofpreparing such product.

These and other objects will be apparent from consideration of thefollowing specification and the appended claims.

In a copending patent application to Howard L. Gerhart, Serial No.324,392, filed March 16, 1940, and entitled Resinous material it isdisclosed that cyclopentadiene copolymerizes with unsaturated glycerideoils or free fatty acids therefrom, to provide resins which are solidsor oils, dependent upon the ratio of oil and other factors. These resinsare unsaturated and in many instances the oily forms have dryingproperties superior even to tung oil. The copolymers of cyclopentadieneand glyceride oils as disclosed in the foregoing application usually areprepared by conjointly polymerizing cyclopentadiene and glyceride oil atatmospheric pressures and in the presence of a halide salt of anamphoteric element as a catalyst.

The present invention is based upon the discovery that cyclopentadieneand unsaturated glyceride oils can conveniently be polymerized byheating them to a suficiently high temperature in a pressure chamber,such as an autoclave or a long tube through which the reactants arecircu lated continuously or intermittently. In this reaction no catalystis required, thus reducing costs, eliminating corrosive and oftenpoisonous efiects and, also, forming a product which is more resistantto water and chemicals than that produced by catalysis.

Glyceride oils that can be employed in the process include linseed oil,soya bean oil, oiticica oil, perilla oil, tung oil, corn oil, cottonseedoil. palm, sardine oil, or the like. The cyclopentadiene and theglyceride oils are mutually highly soluble.

The ratio of oil to cyclopentadiene may vary over a relatively widerange, dependent upon the nature of the product to. be obtained. Forexample, the oil may be as low as of the mixture or as high as 96%.

A good varnish can be obtained with a range of oil of from 30 to 70%.When the oil is below 40%. the resin tends to be a solid which issolublein drying oils and is a useful gum" in the paint industry. When the oilis above 70%. a

"long 011 varnish results. Very long 011 varnishes may he considered tobe new synthetic oils since they have the prope ty of oils rather thanof varnishes. The drying rate of the lon oil modifications is muchfaster than the unmodified oil. "Gums such as the above-described, orrosin, or alkyd resin, or the like can be cooked into it to provide goodvarnish. The procedure is that conventionally employed in the paintindustry in the cooldng oi varnishes.

In the present invention, cyclopentadiene is heated in the presence ofan unsaturated glyceride oil to about 200 to 290 C. in an autoclave butbelow the point oi charring oi the reactants or trimer to form atetramer and soforth. Simultaneously at a temperature above 200 C. thedimer, trimer, tetramer. etc. decompose in part to monomer, which reactswith glyceride oil. In other words in the temperature range of 200 to300 C. there appears to be an equilibrium between the monomer and thedimer, trimer, tetramer, etc. according to this scheme:

Monomerz dimer +monomerlz trimerl monomerlztetramer[+monomerlfipentaxner, etc.

While this invention is not to be limited to any strict explanation ofthe reactions involved it is recognized that two separate reactions maytake lace. Since the pentamer and higher multiples of cyclopentadieneare not soluble in glyceride oil it is desirable that in any thermaltreatment of cyclopentadiene, the amount of pentamer be kept at aminimum. It has been found that this is the case when cyclopentadiene isheated in the presence of glyceride oil. It was found that under theconditions of this invention, substantially all of the cyclopentadieneis reacted with the oil and a very small amount is converted to dimer,trimer, tetramer, pentamer, etc.

Example I A mixture of 492 parts alkali refined unbodied linseed oil and308 parts or cyclopentadiene is charged into an autoclave suitablyequipped. The

charge is heated according to the following schedule with the resultantpressures.

At the end of the bodying period the entire charge is cooled and drainedinto the desired quantity of solvent. A convenient amount is an equalweight of petroleum naphtha or the desired boiling range and flashpoint.

The copolymer thus formed has excellent characteristics as afilm-forming material for both air drying and baking uses. The dryingrate is rapid even when the oil in the charge is a slow drying oil suchas soya oil. A copolymer of soya oil and cyclopentadiene made accordingto this process does not dry with an after tack as do varnishes madefrom soya oil and the present vamlsh gums.

The following compositions are illustrative of the charges which can beused:

It will be appreciated that glycerldes of completely saturated acids,such as stearic acid or lauric acid do not reactwith cyclopentadiene,Where an oil such as cottonseed oil or palm oil is polymerized withcyclopentadiene, it may be desirable to remove some of the unreactedsaturated glycerides from the product. This may be accomplished bychilling and freezing out the higher melting components or by extractingthe unreacted component with a solvent such as ether or a "cellosolve"such as monobutyl ether or ethylene glycol or other oxygenated solvent.

The embodiments of the invention herein disclosed are merely by way ofexample. Numerous modifications may be made therein without departurefrom the spirit or the invention or the scope of the claims.

What I claim is:

1. A process of preparing a copolymer of cyclopentadiene and anunsaturated glyceride oil which comprises heating in a closed systemunder pressure a mixture of cyclopentadiene and unsaturated glycerideoil, the oil constituting about 10 to 96% of said mixture, at atemperature above about 200 C. and below that or charring of the mixtureor the reaction product.

2. A process of preparing a copolymer of cyclopentadiene and anunsaturated glyceride oil which process comprises heating a mixturecomprising cyclopentadiene and said oil, the oil being in a ratio of 10to 96% of the mixture, in a closed system at a pressure above about lbs.per square inch and at a temperature above 200 C. and below that ofcharring of the mixture.

3. A process of preparing a copolymer of cyclopentadiene and anunsaturated glycerlde oil which process comprises heating a mixturecomprising cyclopentadiene and an unsaturated glyceride oil, the oilbeing in a ratio within the Parts I 5 range of 10 to 96% of the mixturein a closed container under pressure within the range of about 25 to 200lbs. per square inch and at a temperature of about 200 to 290 C.

4. A process as defined in claim 1 in which Parts the ratio of oil inthe mixture is 30 to Example II Parts Unbodied alkali refined linseedoil. 600 cyclopentadiene 400 Example II! Parts Unbodied alkali refinedsoya oil. 540 cyclopentadien 450 Example IV Alkali refined medium bodiedlinseed oil- 500 cyclopenta i n 500 Example V Alkali refined unbodiedsoya oil 900 cyclopentadiene The copolymer from this composition is asyn- 5. A process as defined in claim 3 in which the mixture is heatedfor a period of approximately to 275 minutes.

6. A process as defined in claim 3 in which thetic oil which" dries asrapidly as alkali refined 55 heating is continued until a substantialpressure linseed oil.

Example VI 4 Parts Tung ni 1,000 Linseed oil 800.

cyclopentadiene 1,000

drop is observed.

7. A process as defined in claim 3 in which the oil is linseed oil andthe heating operation is continued until a substantial pressure drop is60 observed.

HOWARD L. GERHART.

